Files
linux-stable-mirror/drivers/pinctrl/pinconf.c
T
Oleksij RempelandLinus Walleij ac536de6d4 pinctrl: core: Make pin group callbacks optional for pin-only drivers
Currently, the pinctrl core strictly requires all drivers to implement
.get_groups_count and .get_group_name callbacks in their pinctrl_ops.

However, for simple pinctrl drivers that act purely as GPIO controllers
and pin-specific configuration proxies, without any concept of muxing or
pin groups, this strict requirement forces the implementation of dummy
callbacks just to satisfy pinctrl_check_ops().

Relax this requirement for pin-only drivers by making the group callbacks
optional when no muxing or group pin configuration support is provided.
Update the core and debugfs helpers to check for the existence of these
callbacks before invoking them.

Drivers that provide muxing or group pin configuration operations still
must implement group enumeration and naming callbacks, and are rejected
at registration time if they do not.

Suggested-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Linus Walleij <linusw@kernel.org>
2026-05-25 09:51:22 +02:00

387 lines
9.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Core driver for the pin config portions of the pin control subsystem
*
* Copyright (C) 2011 ST-Ericsson SA
* Written on behalf of Linaro for ST-Ericsson
*
* Author: Linus Walleij <linus.walleij@linaro.org>
*/
#define pr_fmt(fmt) "pinconfig core: " fmt
#include <linux/array_size.h>
#include <linux/debugfs.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/pinctrl/machine.h>
#include <linux/pinctrl/pinconf.h>
#include <linux/pinctrl/pinctrl.h>
#include "core.h"
#include "pinconf.h"
int pinconf_check_ops(struct pinctrl_dev *pctldev)
{
const struct pinconf_ops *ops = pctldev->desc->confops;
/* We have to be able to config the pins in SOME way */
if (!ops->pin_config_set && !ops->pin_config_group_set) {
dev_err(pctldev->dev,
"pinconf has to be able to set a pins config\n");
return -EINVAL;
}
return 0;
}
int pinconf_validate_map(const struct pinctrl_map *map, int i)
{
if (!map->data.configs.group_or_pin) {
pr_err("failed to register map %s (%d): no group/pin given\n",
map->name, i);
return -EINVAL;
}
if (!map->data.configs.num_configs ||
!map->data.configs.configs) {
pr_err("failed to register map %s (%d): no configs given\n",
map->name, i);
return -EINVAL;
}
return 0;
}
int pin_config_get_for_pin(struct pinctrl_dev *pctldev, unsigned int pin,
unsigned long *config)
{
const struct pinconf_ops *ops = pctldev->desc->confops;
if (!ops || !ops->pin_config_get) {
dev_dbg(pctldev->dev,
"cannot get pin configuration, .pin_config_get missing in driver\n");
return -ENOTSUPP;
}
return ops->pin_config_get(pctldev, pin, config);
}
int pin_config_group_get(const char *dev_name, const char *pin_group,
unsigned long *config)
{
struct pinctrl_dev *pctldev;
const struct pinconf_ops *ops;
int selector, ret;
pctldev = get_pinctrl_dev_from_devname(dev_name);
if (!pctldev) {
ret = -EINVAL;
return ret;
}
mutex_lock(&pctldev->mutex);
ops = pctldev->desc->confops;
if (!ops || !ops->pin_config_group_get) {
dev_dbg(pctldev->dev,
"cannot get configuration for pin group, missing group config get function in driver\n");
ret = -ENOTSUPP;
goto unlock;
}
selector = pinctrl_get_group_selector(pctldev, pin_group);
if (selector < 0) {
ret = selector;
goto unlock;
}
ret = ops->pin_config_group_get(pctldev, selector, config);
unlock:
mutex_unlock(&pctldev->mutex);
return ret;
}
int pinconf_map_to_setting(const struct pinctrl_map *map,
struct pinctrl_setting *setting)
{
struct pinctrl_dev *pctldev = setting->pctldev;
int pin;
switch (setting->type) {
case PIN_MAP_TYPE_CONFIGS_PIN:
pin = pin_get_from_name(pctldev,
map->data.configs.group_or_pin);
if (pin < 0) {
dev_err(pctldev->dev, "could not map pin config for \"%s\"",
map->data.configs.group_or_pin);
return pin;
}
setting->data.configs.group_or_pin = pin;
break;
case PIN_MAP_TYPE_CONFIGS_GROUP:
pin = pinctrl_get_group_selector(pctldev,
map->data.configs.group_or_pin);
if (pin < 0) {
dev_err(pctldev->dev, "could not map group config for \"%s\"",
map->data.configs.group_or_pin);
return pin;
}
setting->data.configs.group_or_pin = pin;
break;
default:
return -EINVAL;
}
setting->data.configs.num_configs = map->data.configs.num_configs;
setting->data.configs.configs = map->data.configs.configs;
return 0;
}
void pinconf_free_setting(const struct pinctrl_setting *setting)
{
}
int pinconf_apply_setting(const struct pinctrl_setting *setting)
{
struct pinctrl_dev *pctldev = setting->pctldev;
const struct pinconf_ops *ops = pctldev->desc->confops;
int ret;
if (!ops) {
dev_err(pctldev->dev, "missing confops\n");
return -EINVAL;
}
switch (setting->type) {
case PIN_MAP_TYPE_CONFIGS_PIN:
if (!ops->pin_config_set) {
dev_err(pctldev->dev, "missing pin_config_set op\n");
return -EINVAL;
}
ret = ops->pin_config_set(pctldev,
setting->data.configs.group_or_pin,
setting->data.configs.configs,
setting->data.configs.num_configs);
if (ret < 0) {
dev_err(pctldev->dev,
"pin_config_set op failed for pin %d\n",
setting->data.configs.group_or_pin);
return ret;
}
break;
case PIN_MAP_TYPE_CONFIGS_GROUP:
if (!ops->pin_config_group_set) {
dev_err(pctldev->dev,
"missing pin_config_group_set op\n");
return -EINVAL;
}
ret = ops->pin_config_group_set(pctldev,
setting->data.configs.group_or_pin,
setting->data.configs.configs,
setting->data.configs.num_configs);
if (ret < 0) {
dev_err(pctldev->dev,
"pin_config_group_set op failed for group %d\n",
setting->data.configs.group_or_pin);
return ret;
}
break;
default:
return -EINVAL;
}
return 0;
}
int pinconf_set_config(struct pinctrl_dev *pctldev, unsigned int pin,
unsigned long *configs, size_t nconfigs)
{
const struct pinconf_ops *ops;
ops = pctldev->desc->confops;
if (!ops || !ops->pin_config_set)
return -ENOTSUPP;
return ops->pin_config_set(pctldev, pin, configs, nconfigs);
}
#ifdef CONFIG_DEBUG_FS
static void pinconf_show_config(struct seq_file *s, struct pinctrl_dev *pctldev,
unsigned long *configs, unsigned int num_configs)
{
const struct pinconf_ops *confops;
int i;
if (pctldev)
confops = pctldev->desc->confops;
else
confops = NULL;
for (i = 0; i < num_configs; i++) {
seq_puts(s, "config ");
if (confops && confops->pin_config_config_dbg_show)
confops->pin_config_config_dbg_show(pctldev, s,
configs[i]);
else
seq_printf(s, "%08lx", configs[i]);
seq_putc(s, '\n');
}
}
void pinconf_show_map(struct seq_file *s, const struct pinctrl_map *map)
{
struct pinctrl_dev *pctldev;
pctldev = get_pinctrl_dev_from_devname(map->ctrl_dev_name);
switch (map->type) {
case PIN_MAP_TYPE_CONFIGS_PIN:
seq_puts(s, "pin ");
break;
case PIN_MAP_TYPE_CONFIGS_GROUP:
seq_puts(s, "group ");
break;
default:
break;
}
seq_printf(s, "%s\n", map->data.configs.group_or_pin);
pinconf_show_config(s, pctldev, map->data.configs.configs,
map->data.configs.num_configs);
}
void pinconf_show_setting(struct seq_file *s,
const struct pinctrl_setting *setting)
{
struct pinctrl_dev *pctldev = setting->pctldev;
const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
struct pin_desc *desc;
switch (setting->type) {
case PIN_MAP_TYPE_CONFIGS_PIN:
desc = pin_desc_get(setting->pctldev,
setting->data.configs.group_or_pin);
seq_printf(s, "pin %s (%d)", desc->name,
setting->data.configs.group_or_pin);
break;
case PIN_MAP_TYPE_CONFIGS_GROUP:
seq_printf(s, "group %s (%d)",
pctlops->get_group_name(pctldev,
setting->data.configs.group_or_pin),
setting->data.configs.group_or_pin);
break;
default:
break;
}
/*
* FIXME: We should really get the pin controller to dump the config
* values, so they can be decoded to something meaningful.
*/
pinconf_show_config(s, pctldev, setting->data.configs.configs,
setting->data.configs.num_configs);
}
static void pinconf_dump_pin(struct pinctrl_dev *pctldev,
struct seq_file *s, int pin)
{
const struct pinconf_ops *ops = pctldev->desc->confops;
/* no-op when not using generic pin config */
pinconf_generic_dump_pins(pctldev, s, NULL, pin);
if (ops && ops->pin_config_dbg_show)
ops->pin_config_dbg_show(pctldev, s, pin);
}
static int pinconf_pins_show(struct seq_file *s, void *what)
{
struct pinctrl_dev *pctldev = s->private;
unsigned int i, pin;
seq_puts(s, "Pin config settings per pin\n");
seq_puts(s, "Format: pin (name): configs\n");
mutex_lock(&pctldev->mutex);
/* The pin number can be retrived from the pin controller descriptor */
for (i = 0; i < pctldev->desc->npins; i++) {
struct pin_desc *desc;
pin = pctldev->desc->pins[i].number;
desc = pin_desc_get(pctldev, pin);
/* Skip if we cannot search the pin */
if (!desc)
continue;
seq_printf(s, "pin %d (%s): ", pin, desc->name);
pinconf_dump_pin(pctldev, s, pin);
seq_putc(s, '\n');
}
mutex_unlock(&pctldev->mutex);
return 0;
}
static void pinconf_dump_group(struct pinctrl_dev *pctldev,
struct seq_file *s, unsigned int selector,
const char *gname)
{
const struct pinconf_ops *ops = pctldev->desc->confops;
/* no-op when not using generic pin config */
pinconf_generic_dump_pins(pctldev, s, gname, 0);
if (ops && ops->pin_config_group_dbg_show)
ops->pin_config_group_dbg_show(pctldev, s, selector);
}
static int pinconf_groups_show(struct seq_file *s, void *what)
{
struct pinctrl_dev *pctldev = s->private;
const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
unsigned int selector = 0;
unsigned int ngroups;
if (!pctlops->get_groups_count || !pctlops->get_group_name)
return 0;
ngroups = pctlops->get_groups_count(pctldev);
seq_puts(s, "Pin config settings per pin group\n");
seq_puts(s, "Format: group (name): configs\n");
while (selector < ngroups) {
const char *gname = pctlops->get_group_name(pctldev, selector);
seq_printf(s, "%u (%s): ", selector, gname);
pinconf_dump_group(pctldev, s, selector, gname);
seq_putc(s, '\n');
selector++;
}
return 0;
}
DEFINE_SHOW_ATTRIBUTE(pinconf_pins);
DEFINE_SHOW_ATTRIBUTE(pinconf_groups);
void pinconf_init_device_debugfs(struct dentry *devroot,
struct pinctrl_dev *pctldev)
{
debugfs_create_file("pinconf-pins", 0444,
devroot, pctldev, &pinconf_pins_fops);
debugfs_create_file("pinconf-groups", 0444,
devroot, pctldev, &pinconf_groups_fops);
}
#endif